Loading and unloading device for trucks or other vehicles



R. H. BERG 2,099,993

LOADING AND UNLOADING DEVICE FOR TRUCKQ OR OTHER VEHICLES Nov. 23, 1937.

Filed Feb. 17, 19s? s Sheets-Sheet 1 INVENT OR.

ATTORNEY.

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Nov. 23, 1937; H, ERG 9 2,099,998

LOADING AND UNLOADING DEVICE FOR TRUCKS OR OTHER VEHICLES Filed Feb. 17,1937 3 Sheets-Sheet 2 Illllll lllllllllllllllfllll INVENTOR. E0522 15?.5236 9 v Z W 'MWW ATTORNEY.

Nov. 23, 1937. H. BERG 2,099,998

LOADING AND UNLOADING DEVICE FOR TRUCKS OR OTHER VEHICLES I Filed Feb.17, 19:57 5 Sheets-Sheet s I nmwron P0323?" ZZBEBG ATTORNEY.

Patented Nov. 23, 1937 PATENT OFFICE LOADING AND UNLOADING DEVICE FORTRUCKS OR OTHER VEHICLES Robert H. Berg, San Francisco, Calif.Application February 17, 1937, Serial No. 126,187

13 Claims.

My invention relates to improvements in a loading and unloading devicefor trucks or other vehicles, and it consists of the combinations,constructions and arrangements hereinafter described and claimed.

An object of my invention is to provide a load-- ing the arms forcausing the-arms to lift a load from the ground to the truck.. Ifurther'provide novel means for preventing the yoke from moving out of ahorizontal plane during the eno tire loading operation. This is one ofthe principal features of the invention.

A source of power is used for swinging the arms to lift a loaded palletboard or deckonto the truck, and this same source of power operatingthrough a different mechanism is used for swinging the arms in a reversedirection when unloading the truck. I dispose two parallel channels onthe truck frame and these carry rollers for supporting the loaded decks.A chain is passed 30 around the group of rollers in each channeland Iprovide a source of power for moving the chains and rotating the rollersin order to advance the loaded deck along the truck after it has beenfreed from the lifting arms.

The yokes carried by the arms are pivotally spaced a greaterdistance'apart than the length of the deck. In unloading the decks fromthe truck, the channels carried by the yokes will be disposed beyond theends of the deck. I provide 40 novel means for moving the deck liftingchannels beneath the deck, prior to the swinging of the arms for liftingthe deck from the truck and conveying the deck to the ground.

All of the control mechanisms are placed near due to gravity. I providenovel means for swinging drawings forming a part of this application,

in which Figure 1 is a side elevation of a truck showing my deviceoperatively applied thereto;

Figure 2 is a plan. view of the truck and device;

Figure 3 is' a rear elevation of the truck and device;

Figure 4 is a section along the line 4-4 of Figure 5;

Figure 5 is a section along Figure 4; v Figure 6 is an enlarged sideelevation of one of the deck lifting arms, portions of the cover platebeing broken away for clarity;

Figure 7 is a section substantially along the the line 5-5 of line ofFigure 6 and showing the yoke in elevation; and

Figure 8 is a section along the line 8-8 of Figure 2.

In carrying out my invention I make use of a truck chassis indicatedgenerally at l, and I show the chassis supported by wheels 2. Figure 3shows the chassis formed from two channel irons, and Figure 2illustrates how the chassis carries an axle 3 square in cross section,and secured to the chassis in any manner desired 50 that the axle cannotrotate. At each end of the axle I mount an arm 4 and since both arms areof identical construction, a description of one will suflice. A detailof the arm is shown in Figures 6 and '7.

The arm 4 is in the shape of a casing that is secured to a housing 5that is rotatably mounted I upon an end 6 of the axle 3. Suitablebearings I and 8 are mounted in the housing 5 and rotate on the axle end6. At the free end of the casing 4 I rotatably mount a stub shaft 9..This shaft is mounted in a bearing Hi that is carried by the casing 4.The shaft 9 has a flanged head ll and a yoke i2 is secured to the head.Figure 6 shows a sprocket l3, keyed to the shaft 3 at M and a secondsprocket i5 is keyed to the shaft 9 at It. A sprocket chain H is passedaround both sprockets.

It will be seen in this connection, that a swing ing of the arm 4 by ameans hereinafter described, will cause the sprocket l5 to rotate theshaft 9 because the sprocket I3 is held against rotation since it iskeyed to the nonrotatable shaft 3. The sprocket l3 will rotate as thearm 4 swings and this will hold the yoke II in a horizontalpositionduring the entire swinging of the arm. As already stated this isone of the principal features of the invention.

Y-shaped members 4|.

Figure 6 clearly shows the end |2a of th'e yoke |2 as of greater lengththan the otherid of the yoke. The yoke will therefore have 'a'tendencyto swing in a counterclockwise direction about the shaft 9. This is forthe purpose of causing the upper portion of the chain |'I connecting thetwo sprockets together,. to be held taut during the entire swinging ofthe arms. In this way the yoke i2 will be held against rocking out of ahorizontal plane during the swinging of the arm. v

The yoke l2 carries loadsupporting chains I8 and Figures 1 and 3 showeach pair of chains I3 as supporting deck lifting channels l9. Thechains ineach pair are supported far enough apart to permit them to bereceived in notches in a deck 2| (see the dotted line showing of thedeck in Figure 2).

a The means for swinging the arms 4 from the full line position into thedotted line position in Figure 1 comprises a shaft 22 (see Figure 2)that extends transversely across the truck, the shaft being disposedbetween a head board 23 and a drivers compartment 24 (see Figure l). Theshaft 22 is mounted in bearings 25 and is rotated by a worm and a wormgear (not shown) both being mounted in a housing 26. The worm is rotatedby a sprocket 21 (see Figure 2) and the sprocket is connected by a chain28 to a sprocket 29 which in turn is operatively connected to a powertake-off indicated diagrammatidi'ily at 30. A lever 3| is connected tothe power takeoff 3|) and may be manually operated for connecting thesprocket 23 with a truck engine (not shown) so that the sprocket 29 willrotate in either direction. The lever 3| may also be moved into neutralposition and the sprocket 29 will be disconnected from the engine. Theworm and worm gear in the housing 26 act as an' automatic lock for theshaft 22 for holding the shaft against rotation unless the sprocket 21is rotated.

The mechanisms connecting the shaft 22 with each arm 4 are identical andtherefore a description of one will suffice. A drum 32 is mounted at anend of the shaft 22 and a cable 33 has one end secured to the drum.Figure 1 shows the cable 33 passed over a grooved end 34 of a link 35that is pivoted at 35 to the casing 4. The cable 33 is also passed overa grooved end 31 of a second link 38 that is pivoted at 33 to the casing4. The end of the cable is attached to an eyelet 40 that in turn issecured to the free end of the arm 4.

It will be seen from this construction that a rotation of the shaft 22in a counterclockwise direction when looking at Figure 1, will causeboth drums 32 to wind their cables 33 thereon and to swing the liftingarms 4 from the full line position shown in Figure 1 into the dottedline position. During this movement the links 35 and 38 of each arm 4will be swung into the dotted line position shown and will be supportedby the When the arms 4 reach the dotted line position, the yokes |2 willplace the pallet board or deck 2| on the truck. The

chains l8 will'be freed from the loaded deck because the channel members|3 will drop below the undersurface of the deck and then will swing bygravity into a position directly underneath each yoke l2. Figure 2 showsboth yokes |2 spaced a greater distance apart than the length of thedeck 2|.

The loaded deck will now be supported on rollers 42 that are mounted inchannels 43 (see Figure 2) that extend throughout the length of thetruck. Figure 8 shows an enlarged sectional view of one of the channels43 and it will be noted from this view that each roller 42 consists oftwo enlarged portions 42a and 42b separated by a reduced portion 44. Asprocket 45 is formed on the portion 44. The wheel 42 rotates on a shaft46 that is carried by the channel 43. The shaft is held against rotationby a keeper 4'! that enters a slot 43 in the shaft. A cotter pin 49 ispassed through an opening in the other end of the shaft. 1

Figure 2 shows the rollers 42 disposed in groups of three and thesethree rollers are so arranged as to support a loaded deck. An endlesschain 50 is passed around the sprocket of the rearmost roller and alsopasses over the sprockets of the remaining rollers. A shaft 5| carriestwo sprockets 52 for moving the chains 50 to rotate the rollers. Theshaft is provided with aworm and a worm gear mechanism 53 similar to themechanism 25, and the mechanism 53 is actuated by a power take-oh 54similar to the power take-off 30.

A lever 55 similar to the lever 3| is used for connecting the powertake-ofi 54 with the truck engine (not shown) so that the chains 50 maybe moved in either direction or may remain disconnected from the powertake-off. When the chains 5|) are actuated, the rollers 42 are rotatedin the desired direction and will move the loaded decks as desired.

When connecting-the shafts 22 or 5| to their respective power take-offsfdr causing the shafts to rotate in either direction, it is necessarytodisconnect the engine clutch (not shown). This can be done by astandard mechanism operated by means of a vacuum. I show a lever 56 forcontrolling the vacuum to the clutch disengaging member. It will benoted that all threelevers 3|, 55 and 55 are placed near eachother'where an operator can actuate the levers from a single position.

It should be noted at this point-that when the arms 4 are swung from thedotted line position into the full line position shown in Figure l-, thelinks 35 and 33 associated with each arm will be lifted from theirsupports 4| by flexible connections 51 and '58. The connection 51extends from the arm 4 to the link 38 while the connection 58 connectsthe link 35 to the link 38; The length of the connections 51 and 58 issuch as to position the links in the manner indicated in Figure 1 whenthe arms are ready to lift another loaded deck onto the truck. v

I provide novel means for swinging the arms 4 from the dotted lineposition shown in Figure 1 back into the full lineposition. This meanscomprises a pair of rack bars 53, each bar being slidably disposed in acasing 6|| see Figure 4). The other end of each rack bar is supported ina forked upright 6|. The casing 60 is rockably' mounted on the shaft 22and the upright 5| is carried by the truck chassis Figure 1 shows therear end of the rack bar 59 as being provided with a fork 52. Theupright 6| holds the bar 59 in such a position that the fork 62 willreceive the bearing ll! of the arm 4 as the arm swings from the fullline position into the dotted line position.

Since both racks 53 and associated mechanisms are identical inconstruction, a description of one will suffice for both. When the rackbar 59 is in a fully extended position as shown in Figure 1, a recess 53formed at the front end. of the bar (see Figure 4) will receive a gear64.

This gear is secured to the shaft 22 so as to turn therewith. The gear64 will merely rotate in the recess 63 during the movement of the arm 4from the full line position shown in Figure 1 until the bearing I0 ofthe arm enters the fork 62. At this moment, further movement of the arm4 willalso move the bar 59 and the gear 64 will ride along the rackteeth 65.

I prevent the gear 64 accidently meshing with the teeth 65 before thebearing l0 engages with 1 the fork 62 by providing a spring pressed pawl66 that yieldingly engages with the teeth. When the arm 4 starts to movethe rack bar 59, the pawl 66 will yieldingly engage with the teeth 65 asthe pinion 64 moves along the rack. A leaf spring 61 (see Figure 4) isused for yieldingly holding the bar 59 in engagement with the pinion 64.The bar 59 has a stop 63 that prevents the bar from being entirelywithdrawn from the casing 60. 4

In Figure 5, I show the gear 64 as being of the same diameter as thedrum 32. It will therefore be seen that as the cable 33 is wrapped onthe drum 32, the rack bar 59 will be moved at the same speed so that thebar will permit the arms 4 to be swung into the dotted line position. In

center, the bars 53 control their further movement in a clockwisedirection.

When it is desired to return the arms to the full line position shown inFigure 1, the operator merely actuates the lever 55 (see Figure 2) forreversing the rotation of the shaft 22. This will cause the drums 32 tounwind the cables 33 .and

will further cause the pinions 64 to move the rack bars 59 rearwardlywith'respect to the truck.

The bars 59 through the forks 62 will swing the arms 4 until the armspass dead-center position at which time the arms will continue in theircounterclockwise movement due to gravity.

It will. be noticed during the rear movement of the bars 53 that theywill be swung slightly about the axis of the shaft 22 as a pivot. Thisis due to the fact that the forks 62 when engaging with the arms willdescribe arcs about the axis of the shaft 3. It is only necessary tosupport thefree ends of the bars 59 when'the forks 62 are disconnectedfrom the bearings H! on the arms 4. I provide a projection 69 (seeFigure 1) on each bar 59 and the undersurface of the projection iscurved in the manner shown at Ill. The projection 69 rests in theupright 6| and supports the bar when the arm 4 is disconnectedtherefrom. As soon as the arms Q engage with the forks- 62 and move thebars 59 forwardly with respect to the truck, the bars will swingslightly as they are moved forwardly and the projections 69 will movethrough the uprights 6|. "When the bars 59 are in their forwardmostposition, they will not be supported by the upright 6|.

During the unloading of the decks 2| from the truck, it is possible tomove the deck lifting chanthese fingers into their outermost positions.When the fingers are in their outermost positions, they will straddle adeck 2| (see Figure 3). The arms 4 when in the dotted line positionshown in Figure 1 will permit the chains i8 depending from the yokes |2to pass the members l9 down between the ends of the deck 2| and thefingers 1|. and I2.

The fingers may now be moved toward each other by means of a cableconnected to a cable 86 by pulleys I1 and 18, the free ends of the cable86 being connected to the equalizing bars 13 and 14. The cable 85 ispassed around a pulley l9 and is provided with a handle 80. The operatoron pulling the handle 80 will move the pulley" and cause the cable 86 tomove the equalizing bars 13 and 14 toward each other. This movement willin turn move the fingers 1| and I2 into contact with the ends of thedeck 2| and they will move the members l9 beneath the deck. The fingersH and 12 are held in contact with the deck during the initial movementof the arms 4 from the dotted line position into the full line positionshown in Figure 1. It will therefore be seen that the fingers H and 12act as guides for the members l9 and will cause the members to engagewith the undersurface of the deck 2| during their upward movement. Thefriction of the members l9 against the deck created by lifting theloaded deck, will prevent the members from accidently disengaging fromthe deck until it has been moved onto the ground and the chains I8 andmembers l9 have been freed from their load.

From the foregoing description of the various parts of the device, theoperation thereof may be readily understood. The term truck, wherevermentioned, in the specification and claims is to be construed broadly toinclude all types of vehicles.

During the description of the device the op- :eration has also beenpartially described. In the actual loading of the decks onto the truck.the

until the arms 4 start to lift the deck. The arms will then swing theloaded deck onto the rear 3 of the truck as shown in Figure l. The lever3| may now be moved to disconnect the shaft 22 from theoperatingmech'anism and the lever 55 may be actuated for causing thechains 50 to roentirely loaded. When unloading. the truck, the arms 4will be a in the dotted line position as shown in Figure 1.

The handle 80 is moved for bringing the members I9 beneath the rearmostdeck 2| on the truck and during the initial movement of the arms Qtoward the full line position shown in Figure 1, they will move themembers I!) against the deck.

Further movement of the arms i will transfer the deck to the ground. Thechannels I9 fall free of the deck by swinging outwardly due to gravity.After the loaded deck him been placed on the ground or other supportingsurface, the next load may either be placed on top of the first load orthe truck may be moved forwardly to provide suflicient space for thenext load. The lever 55 is now actuated for moving the chains 50 forrotating the rollers 42 and these will move the next loaded deck towardthe rear of the truck. The arms 4 are again swung into the dotted lineposition shown in Figure 1 and the fingers .II

beneath the loaded deck. The arms I will now lift the next loaded deckfrom the vehicle and .Will place it on the ground. This operation isrepeated untilthe entire truck is unloaded.

While I have shown only the preferred form of my invention, it should beunderstood that various changes or modifications may be made within thescope of the appended claims without departing from the spirit of theinvention.

I claim:

l. A loading and unloading device for vehicles comprising a pair of armspivotally secured to the rear corners of a truck, sprockets placed atthe pivotal axis of the arms and being held against rotation, stubshafts rotatably carried by the free ends of the arms, sprockets keyedto the shafts, chains connecting the sprockets in each arm together, anda load lifting yoke rigidly connected to each stub shaft, said yokesbeing'held in the same angular position with respect to the vehicles bythe chains and sprockets during the entire swinging. of the arms.

2. A loading and unloading device for vehicles comprising a, pair ofarms pivotally secured'to the rear corners of a vehicle, sprocketsplaced at the pivotal axis of the arms and being held against rotation,stub ,shafts rotatablycarried by the free ends of the arms,sprocketskeyed to the shafts, chains connecting the sprockets in eacharm together, and a load lifting yoke rigidly connected to each stubshaft, said yokes being held in the same angular position with respectto the truck by the chains and sprockets during the entire swinging ofthe arms, said yokes being connected to the shafts oif center with thelonger arms of the yokes extending rearwardly from the truck, wherebythe longer arm portions of the yokes will have a tendency to swingdownwardly due to gravity and this will keep one side of the chains tautand prevent the rocking of the yokes into various angular positions withrespect to the vehicle during the movement of the arms.

3. In combination, a pair of arms pivotal about a common axis, anon-rotatable sprocket for each arm and placed at the axis, stub shaftsrotatable carriedby the free ends of said arms, sprockets keyed to theshafts, chains connecting the sprocking yokes pivoted to the free endsof the arms,

means for maintaining the yokes in a horizontal position during theswinging of the arms, and arm liftingmeans comprising a drum for eacharm, a cable for each arm, each cable being secured to one of the drumsand to the free end of the arm associated with the-drum, links pivotedto each arm for supporting intermediate portions of the cables away fromthe axis of the arms, and flexible connections for moving the links intooperative positions as the arms swing outwardly away from the rear endof the vehicle.

5. In combination, a pair of load lifting arms swingable about a commonaxis, a shaft, a drum disposed at each end of the'shaft, a pair ofcables, one being secured to each'drum and to an associate arm forswinging the arms'to lift a load when the cables are wound onto thedrums, and separate means for controlling the movement of the arms whenthey are swung beyond dead center.

6. In combination, a pair of load lifting armsswingable about a commonaxis, a shaft, a drum disposed at each end of the shaft, a pair ofcables, one being secured to each drum and to an associate arm-forswinging the arms to lift a load when the cables are wound onto thedrums, and separate means for controlling the movement of the arms whenthey are swung beyond dead center, said means including guides rotatableon said shaft, rack bars slidable in the guides, pinions keyed to theshaft and designed to mesh with the 'movement of the rods for permittingthe arms to move slowly after passing dead center for gently depositingthe load on the supporting surface, said rod moving means being adaptedto reverso the movement of the rods for reversing the swing ing of thearms for causing them to move beyond dead center, said cable movingmeans controlling the paying out of the cables for permitting the armsto slowly swing due to gravity.

8. In combination, a shaft, a drum mounted thereon, a swingable arm, acable connecting the arm with the drum, means for rotating a shaft forwinding the cable on the drum for swinging the arm beyond dead center, aguide rockably mounted on the shaft, a rod slidable in the guide anddesigned to engage with the arm just before the arm reaches dead center,a pinion secured to the shaft, said rod having a rack portion movableinto meshing relation with the pinion when the rod is moved by the arm,whereby the rotation of the shaft will control the swinging of the armbeyond dead center.

9. In combination, a shaft, a drum mounted thereon, a swingable arm, acable connecting the arm with the drum, means for rotating a shaft forwinding the cable on the drum for swinging the arm beyond dead center, aguide rockably mounted on the shaft, 9; rod slidable in the guide anddesigned to engage with the arm just before the arm reaches dead center,a pinion secured to the shaft, said rod having a rack portion movableinto meshing relation with the pinion when the rod is moved by the arm,whereby the rotation of the shaft will control the swinging of the armbeyond dead center, said shaft rotating means being reversible forcausing the pinion to move the rod and arm in a reverse direction untilthe arm passes dead center, said shaft thereafter controlling therotation of the drum for slowly feeding the cable therefrom forcontrolling the swinging of I the arm after passing dead center.

decks, manually controlled means for moving the 11. In combination, anam moving bar hav ing a rack tooth portion, and a recess adjacent to theportion, a shaft, a guide rockable on the shaft, a pinion secured to theshaft, a spring for yieldingly moving the bar toward the pinion, saidpinion being normally rotatable in the bar recess but meshing with theteeth for moving the bar when the bar is given an initial movement tocause the pinion to mesh with the teeth.

12. In combination, an arm moving bar having a rack tooth portion, and arecess adjacent to the portion, a shaft, a bar guide rockable on theshaft, a pinion secured to the shaft, a spring for yieldingly moving thebar toward the pinion, said 2 pinion being normally rotatablein the barrecess "tuated by the swinging arms but meshing with the teeth formoving the bar when the bar is given an initial movement to cause thepinion to mesh with the teeth, and a spring pressed pin yieldinglyengaging with the teeth for preventing the accidental meshing of thepinion wxlth the teeth.

13. A loading and unloading device for vehicles comprising a pair ofarms pivotally mounted on a vehicle and being spaced far enough apartto'straddle a load, load supporting yokes pivotally secured to the freeends of the arms, means for swinging the arms for raising or loweringthe yokes and the load carried thereby, and means acfor continuouslyholding the yokes in a horizontal position regardless of the angularposition of the'arms, whereby the. yokes are capable of lifting a loadin which the center of gravity is disposed above the connection betweenthe arms and yokes.

' ROBERT H. BERG.

